The spot on the ring could honestly just be a really small, feathered circular shape layer. You'd have to rotoscope it; it's too dark to even attempt motion tracking. Maybe add a masked shine effect if it needs more of a reflective look. It will take quite a bit of time to manually track it to the ring.

For the canvas, you can manually keyframe some masks to reveal the image, or you can use a clip of an ink bleed with an alpha channel to use as a track matte. If the shot is moving, you'll also have to do 3D camera tracking also. Keep that in mind if it hasn't been shot yet.

It seems like you might be in a bit over your head. I'd check out Video Copilot's Basic Training before diving in an trying to achieve more difficult effects.